| Objective To assess the cardioprotective effects and the role of extracellular signal-related kinases (ERK1/2) in emulsified isoflurane preconditioning against ischemia reperfusion injury in rabbits.Methods Fifty-three male New Zealand white rabbits weighing 2500～3000 g were randomly divided into 7 groups:Control group (CON, n=8);Ischemic preconditioning group (IPC, n=8);1.0 MAC Emulsified isoflurane preconditioning group (EPC,n=8);Intralipid group (INT,n=7);2-(2-amino-3-methoxy-penyl)-4H-1-benzopyran -4-one(PD 98059) group (PD 98059, extracellular signal- related kinases antagonist,n=7); Dimethylsulfoxide group (DMSO,the menstruum of PD 9805- 9,n=7);The combination of PD 98059 and 1.0 MAC Emulsified isoflurane preconditioning group(PD+EPC,n=8) .The rabbits were subjected to 30 min of myocardial ischemia induced by temporary ligation of the left anterior descending coronary artery(LAD) followed by 180 min of reperfusion.The heart rate(HR),systemic arterial blood pressure(SBP) and mean arterial blood pressure(MAP) were recorded at the end of baseline,the time of ischemia,ischemia 30 min and at 60 min,120 min ,180 min after reperfusion; the rate-pressure product(RPP) were calculated.Blood were taken from carotid artery at reperfusion 180 min for measuring serum creatine kinase(CK),lactate dehydrogenase(LDH) activities. Infarct size(IS) was determined by 2,3,5-triphenyltetrazoliu m(TTC) staining at 180 min after reperfusion. Results Hemodynamics: there were no significant difference among seven groups(P >0.05),compared to baseline, HR,MAP,RPP were dropped step by step after ischemia and reperfusion(P <0.05). Myocardial infarct size and serum CK,LDH activities: Compared to group CON,the IS/AAR and serum CK,LDH activities of group IPC and EPC were declined significantly(P <0.05), there were no significant difference among group INT,PD,DMSO and PD+EPC in IS/AAR and activities of CK and LDH(P >0.05).There were no difference between group IPC and EPC in IS/AAR and activities of CK and LDH(P >0.05). Compared to group EPC, the IS/AAR and serum CK,LDH activities of group PD+EPC were increased obviously.(P <0.05)Conclusion 1.0 MAC Emulsified isoflurane preconditioning can provide myocardial protection against ischemia reperfusion injury in rabbit hearts in vivo,the myocardial protection of emulsified isoflurane preconditioning may be concerned with activating extracellular signal-related kinases (ERK1/2). |
PDF Full Text Request